N. Atlantic Cod Will Likely Never Recover - New Species Have Lock On Area

[hatrack]

"Overfishing has so profoundly altered Canada's East Coast ecosystem it is an open question whether the cod will ever return, says a study on the demise of one of the world's greatest fisheries. Small fish and bottom-feeders, such as crab and shrimp, have flourished in the cod's absence and appear to have a "lock on the system" that is preventing recovery, says Kenneth Frank, a senior scientist with the federal Fisheries Department. He is the lead author of the report published today in the journal Science.

The study details how the decimation of cod stocks in the 1990s has had a domino effect which radically restructured the marine food web. This is the first time such a "trophic cascade" has been documented in an open-ocean ecosystem.

Cod was for centuries the most abundant predator in the East Coast marine ecosystem and supported a thriving fishery. The stocks, which were still plentiful in the early 1980s, crashed a few years later and a moratorium was placed on cod fishing in 1993. Fish managers and fishing communities hoped the cod would bounce back if nets were kept out of the water for a few years. But 12 years into the moratorium, the cod show no sign of recovery and key stocks are listed as endangered and threatened.

EDIT

The Science paper says it is "an open question" whether the ecosystem changes are reversible. Frank said in an interview the system is far too complex to understand. But he believes the crab, shrimp and small fish are preventing the cod from reproducing successfully. "The little guys have got a lock on the system that makes recovery difficult," he says, explaining that the new dominant species are swallowing the young the cod manage to produce."

EDIT

http://www.canada.com/edmonton/edmontonjournal/news/story.html?id=eb1a7f51-74ed-45d0-b4a6-83b9371ff55d

[phantom power]

1. Basins of attraction can be a real bitch.

We're flipping all sorts of systems into new stable-states, and they aren't just going to flip back for us when we decide we don't like the new "normal".